This invention relates to new derivatives of mitomycin C.
The new derivatives of mitomycin C contemplated by the present invention are la-higher aliphatic acyl derivatives of mitomycin C having the general formula: ##STR2## wherein R is an aliphatic saturated or ethylenically unsaturated hydrocarbon group having 9-29 carbon atoms, preferably, 9-21 carbon atoms or a group wherein a hydrogen atom of said aliphatic hydrocarbon group is substituted by a hydroxy group.
Mitomycin C is a compound which is well known to have a very strong antibacterial activity against Gram-nagative and Gram-positive bacteria. The compound is also well known, particularly, to have a remarkably strong anti-tumor activity. However, because mitomycin C at the same time is very toxic, there have heretofore been proposed various derivatives of mitomycin C which have less toxicity. For example, U.S. Pat. No. 3,514,452 discloses la-lower aliphatic acyl derivatives, such as la-acetyl and la-butyryl derivatives of mitomycin C. These compounds have much less toxicity than mitomycin C.
However, these la-lower aliphatic acyl derivatives of mitomycin C are not satisfactory in respect of the anti-tumor activity and the lipid-solubility and, therefore, an improvement is still desired.